How to access HBase columns in Hive,

Category : Hadoop | Sub Category : Apache HBase | By Prasad Bonam Last updated: 2023-08-16 08:44:31 Viewed : 714

To access HBase columns in Hive, you can use the HBase storage handler provided by Hive. This allows you to create Hive tables that are backed by HBase tables, enabling you to query and analyze HBase data using Hives SQL-like language. Here is an example of how to call HBase columns in Hive:

Assumptions:

• You have HBase and Hive installed and configured to work together.
• You have an HBase table named hbase_table with data.

1. Create an External Hive Table Using HBase Storage Handler:

Assuming you have an HBase table named hbase_table with a column family cf1, you can create an external Hive table that maps to the HBase data using the following steps.

sqlCopy code
CREATE EXTERNAL TABLE hive_hbase_table (
    rowkey STRING,
    cf1_col1 STRING,
    cf1_col2 STRING
)
STORED BY `org.apache.hadoop.hive.hbase.HBaseStorageHandler`
WITH SERDEPROPERTIES (
    "hbase.columns.mapping" = ":key,cf1:col1,cf1:col2"
)
TBLPROPERTIES ("hbase.table.name" = "hbase_table");

In this example:

• rowkey is the Hive column corresponding to the HBase row key.
• cf1_col1 and cf1_col2 are the Hive columns corresponding to the columns within the cf1 column family in HBase.

2. Query HBase Columns Using Hive:

You can now use Hive is SQL-like language to query HBase data as if it were a regular Hive table.

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SELECT rowkey, cf1_col1, cf1_col2
FROM hive_hbase_table
WHERE cf1_col1 = `value`;

Keep in mind that the org.apache.hadoop.hive.hbase.HBaseStorageHandler class should be available on your Hive classpath. Also, ensure that the hbase-site.xml and other necessary HBase configurations are accessible to Hive.

This example demonstrates the basic process of accessing HBase columns in Hive. Depending on your use case, you might need to adapt the column mapping and table properties to match your HBase schema. Always refer to the Hive and HBase documentation for the latest and detailed information on setting up HBase storage handlers and using them with Hive.